Dear Mr. Dilip,
Please find below response to your queries
1. To whom does the copyright belong under the international copyright law state?
Copyright belongs to original author. it is just translation to other language, any language expert could have helped.
2. What does the Indian copyright law say about this issue?
Copyright law protects internationally under Berne's Convention law.
3. What does the Indian law say with respect to fair use of the translated material.
For the translation & distribution of book there should be prior approval from the original author. Definitely you need to pay royalty.
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Trademark Attorney & IP Lawyer
IP Lex Global Services